-- !!! RW files module Main(main) where import System.IO import System.Directory ( removeFile, doesFileExist ) import Control.Monad main = do f <- doesFileExist "readwrite001.inout" when f (removeFile "readwrite001.inout") hdl <- openFile "readwrite001.inout" ReadWriteMode hSetBuffering hdl LineBuffering hPutStr hdl "as" hSeek hdl AbsoluteSeek 0 ch <- hGetChar hdl print ch hPutStr hdl "ase" hSeek hdl AbsoluteSeek 0 putChar '\n' ls <- hGetContents hdl putStrLn ls